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Some bacteria like it cold

A scanning electron microscope image of the Chryseobacterium greenlandensis bacteria found in a Greenland glacier.

Sara LaJeunesse

August 18, 2008

Some bacteria like it cold

Talk about going to extremes. A Penn State research team led by molecular biologist Jean Brenchley has discovered a new species of bacteria two miles deep in a Greenland glacier, where it has survived for over 120,000 years.

The bacterium, dubbed Chryseobacterium greenlandensis, is of a ubiquitous yet little-known type known as ultra-small bacteria, so tiny that their cells can pass unhindered through microbial filters. (Some have even been found living in the ultra-purified water used for dialysis.)

The new species is genetically related to similar bacteria found in fish, marine mud, and the roots of some plants, and is one of only about 10 known species originating from polar ice and glaciers. To study it in the laboratory, Brenchley’s team, including senior research associates Jennifer Loveland-Curtze and Vanya Miteva, filtered the organism from melted ice samples and incubated it in solution. They then characterized its genetic, physiological, biochemical, and structural features. Its ability to persist in a low-temperature, high-pressure, reduced-oxygen, and nutrient-poor natural habitat, the researchers say, makes C. Greenlandensis particularly useful for studying how life, in general, can survive in extreme environments—on Earth and possibly elsewhere in the solar system.

"Microbes comprise up to one-third or more of the Earth's biomass, yet fewer than eight thousand microbes have been described out of the approximately three million that are presumed to exist," says Loveland-Curtze. "The description of this one species is a significant step in the overall endeavor to discover, cultivate, and use the special features held by these organisms."

Kendrick Taylor, University of Nevada-Reno/National Oceanic and Atmospheric AdministrationPaleoclimatology Program/Department of Commerce

Ice samples are extracted from deep within the Greenland glacier by a specialized drill, lowered on a heavy cable. Here the core barrel, filled with a new sample, is carefully removed from the drill apparatus. Note: Access to ice-core samples was provided by the National Science Foundation.